The implementations described herein relate generally to forming a joint between two or more mechanical components, and, more specifically, to forming a direct bearing joint between a load-bearing component and composite component.
At least some known aircraft are designed and manufactured using large amounts of composite materials. For example, composite materials are used in an aircraft to decrease the weight of the aircraft. Decreasing the overall weight may improve performance features, such as, for example, payload capacities and fuel efficiencies. At least some known aircraft include a fuselage structure including a thin load-bearing composite skin supported by circumferential bulkheads designed to transfer shear stresses and to retain the shape of the fuselage. Major load carrying metal components, such as wings spars, the keel beam, and wheel well longerons, for example, are coupled to both the bulkheads and the composite skin to distribute concentrated loads to the composite skin.
During at least some known metal or composite aircraft construction, bulkheads, major load bearing components, and composite skin are joined together via metal fasteners. As the amount of load to be distributed increases, the number and size of fasteners required to join the components together increases. However, because fasteners have a minimum spacing allotment from each other and from the skin edge, increasing the size and number of fasteners also increases the overall size and weight of the joint required to join the components. In some cases, the joint may become impractical because of space limitations if for example, the larger joint may interfere with other systems of the aircraft. Furthermore, in at least some known aircraft, a gap may be defined between the skin and the structure transferring load to the skin, such that the load path extends only through the fasteners that couple the skin to the structure. In such cases, if one or more of the fasteners fail, the load would be distributed to the remaining fasteners, thus increasing the risk of their failure as well.
At least one known construction solution is to distribute the concentrated load over multiple locations along the aircraft such that each location has less load to bear. However, such a construction method still results in a net increase of fasteners that are distributed across additional joints. Moreover, in similar cases the additional joints may also interfere with other aircraft systems, such as the landing gear. As such, increasing the quantity of fasteners or the size of the fasteners to join various aircraft components generally result in a significant increase in weight, complexity, and cost penalties for larger loads.